Hannafin J A, Arnoczky S P, Hoonjan A, Torzilli P A
Laboratory for Comparative Orthopaedic Research, Hospital for Special Surgery, New York, New York, USA.
J Orthop Res. 1995 Nov;13(6):907-14. doi: 10.1002/jor.1100130615.
The effect of stress deprivation and cyclic tensile loading on the mechanical and histologic properties of the canine flexor digitorum profundus tendon was examined using an in vitro system. Stress deprivation resulted in a progressive and statistically significant decrease in the tensile modulus over an 8-week period. Histologically, stress-deprived tendons demonstrated quantitative changes in the morphology and number of cells and in the alignment of collagen. The change in tensile properties was not associated with an alteration in the water content of the tissue, but the change appeared to be dependent on the presence of a viable cell population. Dead (acellular) tendons did not undergo any alteration in tensile modulus in this in vitro system. In vitro cyclic tensile loading of tendons over a 4-week time period resulted in a significant increase in the tensile modulus (93% of the control) compared with that of the stress-deprived tendons (68% of the control). This loading regimen also maintained the normal histologic pattern of the tendons. The results of this study are similar to those previously reported for in vivo studies and suggest that this in vitro model may represent a valid system with which to test the effects of various stress conditions on the tensile properties of tissues.
使用体外系统研究了应力剥夺和循环拉伸加载对犬指深屈肌腱力学和组织学特性的影响。在8周的时间里，应力剥夺导致拉伸模量逐渐且具有统计学意义的下降。组织学上，应力剥夺的肌腱在细胞形态、数量以及胶原排列方面表现出定量变化。拉伸性能的变化与组织含水量的改变无关，但这种变化似乎依赖于活细胞群体的存在。在这个体外系统中，死亡（无细胞）的肌腱拉伸模量没有发生任何改变。与应力剥夺的肌腱（对照组的68%）相比，在4周的时间段内对肌腱进行体外循环拉伸加载导致拉伸模量显著增加（达到对照组的93%）。这种加载方案还维持了肌腱正常的组织学模式。本研究结果与先前体内研究报告的结果相似，表明该体外模型可能是一个有效的系统，可用于测试各种应力条件对组织拉伸性能的影响。
